This invention relates generally to electrophotographic printing, and more particularly, concerns cleaning imaging (i.e. photoreceptive, photoconductive, etc.) and bias transfer roll (BTR) surfaces using air velocity.
High velocity air streams have been used to clean photoreceptors in the past. Although several attempts have been made to clean photoreceptors and bias transfer rolls (BTRs). These devices, photoreceptors and BTRs, have used air knives to create a high velocity air stream to clean their surfaces. Such devices can consist of a plate, closely spaced to the surface to be cleaned, with narrow slots cut into it. A vacuum is applied behind the plate to cause air to flow through the slots and create a high velocity airstream across the surface being cleaned. The high velocity air flow disturbs the surface boundary layer allowing removal of particles adhered to the surface.
The problems with this approach are in the manufacture of the device and the power required to create the vacuum. The tolerances for the cleaner and the surface to be cleaned must be held closely. The orifice slot width must be uniform along its length to maintain uniform air velocities and therefore cleaning. The spacing between the plate and surface to be cleaned must also be uniform for the same reasons. This requires the plate and cleaning surface to be straight, flat and well aligned. If the surface to be cleaned is a roll, the runout of the roll and the parallelism of the roll axis to the slot axis is also important. Because of the close spacing of the cleaning plate to the surface to be cleaned and the narrow orifice slot, the resistance of the system to air flow is very high.
As a result of this high resistance to air flow, a considerable air flow is required to generate the required cleaning air velocities needed for the narrow orifice slot to clean the surface. The requirements of high pressure and air flow result in a high power usage for the system and the possibility of a noise problem.
An object of the fiber removal device which can remove fiber before fiber can interfere with development wires associated with HSD development systems thereby reducing fiber related streak defects.
There is provided an air suction manifold device for removal of fibers/debris from the photoreceptor surface, which may otherwise attach to the development electrode wires causing a print defect(s). The device incorporating a secondary channel perpendicular to the main channel, formed by the manifold flange(s) proximity to the photoreceptor surface. The secondary channel supplying a specific volume of air at a specific mean velocity in a direction perpendicular to the flow direction of the main channel. The volume and velocity of secondary channel air being of such magnitude that it crosses the main channel gap and impinges on the photoreceptor surface, causing a zone of maximum shear stress prior to completely mixing with the main channel air. The maximum sheer stress zone resulting in improved fiber/debris removal performance from the photoreceptor surface.